British long-range target cartridge. "LSR" is believed to stand for Long School Record. Used in single-shot target rifles at British ranges.
Type: Rifle
Introduced: 1900, United Kingdom
Parent case: None
Standardization: None
Bullet diameter: 0.375" (9.53 mm)
Max pressure: 25,000 PSI
Rim type: Rimmed
Primer: Large Rifle
Typical twist rate: 1:12
Muzzle velocity: 1800–2000 fps
Muzzle energy: 1870–2332 ft-lbs
Effective range: 300 yd
Common bullet weights: 270, 300 gr
Primary use: target
Production status: Obsolete
Also known as: 375 LSR · .375 Long School Record
History: A specialized proprietary cartridge from the late 19th century, developed for a specific long-range sporting rifle system. Used in single-shot target rifles for 1,000-yard competition. Represents the era of highly specialized target cartridges before .308 Winchester standardized long-range competition.